The present invention concerns a throttle valve system. It comprises a throttle valve housing, a valve stem, a valve disk, a disk adjustment mechanism, a gas mixture chamber, an angle detector, electronic controls, a temperature sensor, and a valve unit. The valve disk is mounted on the stem, which can be adjusted (rotated) within the gas mixture chamber inside the valve housing. The disk adjustment mechanism and the angle detector are at least partly attached to the stem. The controls are accommodated in the valve housing.
A throttle valve system of this type is known from the published international Application No. PCT/EP94/03825. It comprises a valve housing, a stem, a disk, a disk adjustment mechanism, motor controls, and an angle detector. The disk is mounted on the stem inside the valve housing. The disk adjustment mechanism and the rotating component of the angle detector are attached to the stem. The stationary component of the angle detector is accommodated in the valve housing.
A disk adjusting mechanism is known from the published German Patent Application 4,403,604 A1. An uncoupled throttle valve adjustment mechanism as mounted on a stem. The position of the stem is varied by controls in accordance with specific curves.
A throttle valve system may also include a temperature sensor mounted on the outside of the valve housing.
Although these systems are in themselves successful, they entail the drawback that all the electrical connections have to be separate. The systems are more expensive to install, likelier to fail, and more difficult to maintain.
The throttle valve system also includes a valve that forwards vapors from the fuel tank to a gas mixture chamber. This valve is of course remote from the valve housing and must communicate through a hose. The valve must be separately mounted and, like the outside temperature sensor, is separately connected to the controls.